gluloadsamplingmatrices(3G)



gluLoadSamplingMatrices(3G)    OpenGL Reference    gluLoadSamplingMatrices(3G)



NAME
     gluLoadSamplingMatrices - load NURBS sampling and culling matrices


C SPECIFICATION
     void gluLoadSamplingMatrices( GLUnurbs* nurb,
                                   const GLfloat *model,
                                   const GLfloat *perspective,
                                   const GLint *view )


PARAMETERS
     nurb         Specifies the NURBS object (created with
                  gluNewNurbsRenderer).

     model        Specifies a modelview matrix (as from a glGetFloatv call).

     perspective  Specifies a projection matrix (as from a glGetFloatv call).

     view         Specifies a viewport (as from a glGetIntegerv call).


DESCRIPTION
     gluLoadSamplingMatrices uses model, perspective, and view to recompute
     the sampling and culling matrices stored in nurb.  The sampling matrix
     determines how finely a NURBS curve or surface must be tessellated to
     satisfy the sampling tolerance (as determined by the
     GLUSAMPLINGTOLERANCE property).  The  culling matrix is used in
     deciding if a NURBS curve or surface should be culled before rendering
     (when the GLUCULLING property is turned on).

     gluLoadSamplingMatrices is necessary only if the GLUAUTOLOADMATRIX
     property is turned off (see gluNurbsProperty).  Although it can be
     convenient to leave the GLUAUTOLOADMATRIX property turned on, there
     can be a performance penalty for doing so.  (A round trip to the OpenGL
     server is needed to fetch the current values of the modelview matrix,
     projection matrix, and viewport.)


SEE ALSO
     gluGetNurbsProperty, gluNewNurbsRenderer, gluNurbsProperty














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